What is PD?

PD stands for Pupillary Distance, which is distance in millimeters (mm) between the centers of the pupils in each eye. PD numbers do not change for adults. The average PD range for adults is 55-75 mm and for kids is about 42-55 mm. A difference of 2-3 mm is acceptable.

Why a prescription Glasses need PD data?

PD- Pupillary Disctance is necessary for prescription glasses, it tells the lens maker where to put the optical center on each lens.

What is PD?

PD stands for Pupillary Distance, which is distance in millimeters (mm) between the centers of the pupils in each eye. PD numbers do not change for adults. The average PD range for adults is 55-75 mm and for kids is about 42-55 mm. A difference of 2-3 mm is acceptable.

Why a prescription Glasses need PD data?

PD- Pupillary Disctance is necessary for prescription glasses, it tells the lens maker where to put the optical center on each lens.

How to Measure Your PD?
step 1

Down load our PD ruler Or find a ruler with a millimeter scale.

step 2
Mirror or Friend

Stand 8 inches (20 cm) away from a mirror or a friend. Place & hold the PD ruler against your brow. Keep your face straight.

step 3
Align to Zero

First, close your right eye and align the ruler’s zero to the center of your left pupil.

step 4
Open Right, Close Left

Next, open your right eye and close your left eye.

step 5
Your PD

Look straight ahead and read the millimeter line that matches up with the center of your right pupil. This number represents your single PD in millimeters.